alt Hacker NewsYep, they are quite bad without stockfish. You can test it with the playchess skill in my repo. Maybe 1200/1300, who knows? Still I do think that they can, with enough time, explore multiple variations where they confront their naivety to stockfish and build up a compact picture on why move Y should have been played instead of move X. That was my intuition when building this skill.
Have you actually tested this with quiet positions, where understanding needs to be more about different strategic or positional choices? They can explain concrete tactical lines with stockfish analysis at hand, but so can an analysis board. In my experience, even with fairly deep and accurate engine analysis, they cannot do this accurately with quiet positions. I tried to build a product around this idea and I'm convinced that even if it is possible it would require hundreds of thousands - or millions - spent on post-training to even confirm that possibility.